Research On Preparation And Performance Of Bionic Metal Sulfide Photoelectric Detection Materials

Photodetector(PD),as an important element of optoelectronic device,has important applications in the fields of sensing,imaging and automation control.In recent years,integration and functionalization have made high performance,miniaturization,and flexibility the main development trend of photodetectors.Metal sulfides benefit from their inherent excellent optical and electrical properties,as well as their controllable morphology,structure and composition,and become more and more important in the field of emerging photodetectors.However,traditional metal sulfides have problems such as poor light trapping ability and small light response range.In addition,the relative displacement of the material will cause its micro-nano structure to be destroyed,which limits its use in high-performance,miniaturization,and flexible photodetectors.Therefore,there is an urgent need to develop a new structure of metal sulfide to construct a photodetector.In this thesis,combining electrochemical,hydrothermal,chemical vapor deposition(CVD)and other preparation methods,a new type of bionic metal sulfide photoelectric functional material is designed using the bionic design idea inspired by nature.This work also systematically studied the construction and performance of high-performance photodetectors based on metal sulfides.The work of this paper is as follows:1.Aiming at the problem of unstable photoelectric performance in the common bending process of flexible photoelectric detection.In this work,inspired by the divergent light-trapping structure of marigold and its spherical quasi-periodic symmetry,a flower-like molybdenum disulfide(Mo S₂)with both flexibility and high light absorption was designed and used hydrothermally.The Mo S₂nanoflower can ensure the stable electrical performance of the flexible photodetector when it is bent while maintaining high efficiency of light absorption,and the carefully designed asymmetric electrode connection structure allows the sensor to operate without external energy supply.The test results show that the bionic design enables Mo S₂nanoflowers to achieve strong broadband and omnidirectional absorption(92.7%),and ensures that the PD maintains stable physical contact under different bending degrees.The Mo S₂nanoflower-based PD has excellent flexibility and stability.Even if the device is bent to 151°,it can still maintain an initial efficiency of 91.4%,and after 1000bending cycles,it can still maintain an initial efficiency of 92.5%.The device also has excellent photoelectric response when there is no applied bias.This work provides an important solution for the use of bionic design to solve the problems of poor bending resistance and unstable light absorption of flexible PD.2.At present,semiconductor materials are facing the inability to break through the limitation of their own band gap for wide-band detection.In this work,inspired by the insulation properties of polar bear fur,a hair-like anodic aluminum oxide(AAO)structure was originally designed and combined with cadmium sulfide(CdS)to construct a photodetector.The main point of the design is:combining the high optical transmittance of the hair-like AAO with the low thermal conductivity of the material itself,not only can reduce the propagation loss of light on the AAO to improve the light absorption of the light-responsive material in the device,but also to achieve the effect of"heat preservation"to reduce the thermal energy dissipation of CdS,thereby broadening its light response wavelength range.In addition,the contact interface between AAO and CdS can also effectively promote the accumulation of holes and reduce the recombination rate of carriers of the device,thereby improving the detection efficiency of the device.The detector utilizes the coupling effect of photoelectric effect and photothermal effect,not only has excellent response in detecting ultraviolet and visible light,but also can detect weak infrared heat distribution changes of the human body.It also overcome the limitation of the material's own band gap,and realize broadband detection,successfully.In addition,the asymmetric silver electrode used in the construction of the photodetector gives the device a self-powered characteristic.Therefore,this work provides a new solution for realizing high-performance,miniaturized and wide-band photodetectors.To sum up,this paper uses the characteristics of easy preparation of metal sulfides and controllable morphology.Firstly,it is inspired by the unique structure of marigold divergence,and the PD based on Mo S₂nanoflowers is designed and fabricated,which solves the problem of insufficient bending stability and optical stability of flexible PD.The problem of poor absorption capacity;then based on the thermal insulation characteristics of polar bear hair,a hair-like AAO was designed,and the AAO/CdS self-powered photoelectric thermal detector with enhanced coupling of photoelectric effect and pyroelectric effect was successfully realized,which greatly expanded the use of CdS materials.Response range and response rate.Combining the bionic design ideas and the characteristics of metal sulfides,this thesis innovatively designs a series of high-performance PDs with high stability,wide band and low angle dependence and their constituent materials,which are of great significance for the realization of integrated and functional PDs.